مشخصات پژوهش

Electrochemical measurements have advantages for the determination of antioxidant activity such as their use as a rapid proof of the antioxidant capacity of a lot of organics. The oxidation potentials measured by cyclic voltammetry (CV) have been used to compare the antioxidant strength of compounds such as phenolic acids, flavonoids, cinnamic acids, etc. [1,2], being the glassy carbon electrode (GCE) the more frequently used electrode. Helianthus annuus (Asteraceae) is an annual plant native to America. [3]. It possesses a large inflorescence. The leaf which is simple, heart-shaped, lobated, and alternate along the stem has been of interest to researchers because of its uses in the treatment of various disease conditions in Nigerian traditional medicine. Its leaf is used by the herbalist for the treatment of diabetes mellitus in Enugu State, Nigeria[4]. In the present work the electrochemical oxidation of aqueous-methanolic leaf extract of Helianthus annuus has been investigated by cyclic and differential pulse voltammetry (DPV) techniques. The results show that this extract has strong scavenging capabilities and oxidized at low potentials in comparison of quercetin as a standard antioxidant. Also the effect of extract concentration and scan rates has been studied in the biological pH.